Many electronic devices include complex systems for processing, storing, and displaying data. One of these systems regulates power, such as through power regulation circuits. These power regulation circuits regulate battery or external power, including through use of lower-voltage power rails from which components of the device operate. Some components of the device, however, are able to operate across a wide range of power states or performance profiles to improve user experience and device performance. For example, a graphics processor of the device may operate at increased voltage and frequency levels to render visual content at a higher frame-rate in order to display more realistic graphical effects. Alternately, the graphics processor may operate at reduced voltage and frequency levels to conserve power, such as to extend device runtime when operating from battery power so the user can watch an entire movie without recharging the device.
Adjusting voltage levels of the power regulation circuits, however, often requires careful coordination between the regulation circuits and the components that draw power from those regulation circuits. In some cases, a voltage level of a power regulation circuit is increased or decreased before a component is permitted to draw operating current from the power regulation circuit. In such cases, the voltage level of the regulation circuit may float or decay slowly due to a lack of load on the output of the regulation circuit. To address this issue, the power regulation circuit may be programmed to wait a predetermined amount of time before indicating that the voltage level of the power regulation circuit has been increased or decreased to support operation of the component.
Aside from not actually knowing if the voltage level is correct during or after the wait time, the predetermined amount of wait time introduces other issues that affect device performance. For example, if the predetermined wait time is too short, application of the component's current load can drag a floating voltage level at the output of the power regulation circuit down rapidly resulting component brownout or shutdown. In other cases, a predetermined wait time that is too long allows the power regulation circuit to operate without providing power to the load, which wastes power of the device as the power regulation circuit is allowed to idle. As such, these time-based methods for managing voltage adjustments of power regulation circuits can impair device performance in numerous ways.
This description of related art is provided for the purpose of generally presenting a context for the disclosure that follows. Unless indicated otherwise herein, concepts described in this section are not prior art to this disclosure and are not admitted to be prior art by inclusion herein.